1. Field of the Invention
The present invention relates to a substrate processing apparatus and method for performing a curing process on a target film formed on a substrate, such as a semiconductor wafer, to cure the target film.
2. Description of the Related Art
As a method for forming an inter-level insulating film on, e.g., a semiconductor wafer (which may be referred to as “wafer”), in the process of manufacturing semiconductor devices, there is an SOD (Spin on Dielectric) method that comprises steps of forming a coating film on a wafer by spin coating and performing a chemical process or heating process on the film, thereby forming an inter-level insulating film.
According to this method, at first, a coating liquid formed of a solvent with a material dispersed therein for forming an insulating film is applied on the surface of a wafer, and then the solvent of the coating liquid is dried up. Then, the coating film (target film) is heated to perform a baking process for causing a chemical reaction. Then, the coating film is heated to perform a curing process for curing the film, thereby forming a predetermined insulating film.
As a curing apparatus for curing a coating film in the process of forming an insulating film, there is an EB curing apparatus for performing a curing process by use of an electron beam (see Jpn. Pat. Appln. KOKAI Publication No. 2004-186682).
According to the EB curing apparatus, a wafer is placed inside a process chamber having a predetermined vacuum atmosphere, and an electron beam is radiated from an electron beam generation unit onto the target surface of the wafer to perform a curing process. An EB curing process is thus performed on a coating film (target film) formed on the wafer, so that the insulating film is cured.
The EB curing process entails a problem in curing an insulating film having a low specific dielectric constant (k-value) (which may be referred to as “Low-k film”), such that an electron beam radiated onto the film tends to damage the film.
In light of this, an UV curing process is commonly used for a Low-k film in place of the EB curing process. The UV curing process is arranged to radiate UV rays (ultraviolet rays) onto a coating film to perform film curing without damaging the Low-k film.
However, the UV curing process requires the illumination intensity of UV rays to be higher to increase the processing rate. Consequently, another problem may arise such that the temperature of the radiation target object becomes unnecessarily higher.
Further, in order to control the temperature increase of the radiation target object, a cooling function needs to be added, so the apparatus becomes more complex and thereby brings about an increase in cost.